Biotic and Abiotic Factors

Part of the Ecology Disrupted Curriculum Collection.

biotic abiotic main image


Biotic and Abiotic Factors teacher's guide



  1. A. Introduce the ecological principles of biotic and abiotic factors
  2. B. Connect the principles to this case study about Baltimore streams.


Key Idea: Ecosystems have a natural balance of abiotic and biotic factors.

Question: What is the definition of an ecosystem?
Answer:  An ecosystem is an area that includes all the interconnected living (biotic) and non-living (abiotic) components.

Question: In science we call living things biotic factors and the non-living things abiotic factors.  What are some abiotic and biotic factors in the Baltimore stream ecosystem?

  • Biotic: fish, plants, algae, bacteria
  • Abiotic: salt, water, rocks, sediment, trash

Ecosystems need a balance of both types of factors to be healthy. The ecosystems that we have been exploring are the fresh waterways around a city – in this case the city of Baltimore.